1. Field of the Invention
This invention relates to a device for use with an apparatus such as a position encoder, a laser interferometer or the like in which a detector outputs two sine signals out of phase with each other in accordance with a position change (generally, the signals from said detector are not pure sine signals but are quasi-sine signals, whereas herein signals including such quasi-sine signals are referred (to as sine signals) to indicate the amount and direction of displacement. The device forms the ratio of the sine signals to enable greater resolution and accuracy in the determination of displacement.
2. Description of the Prior Art
A device for dividing and for reading out the signals from a position encoder is known in which two sine signals, out of phase with each other by 90.degree., obtained from a detector are applied to a resistor array to thereby form sine signals of various phases, and all the zero crossing points of these signals are counted.
However, such conventional divisional reading device has required a great number of divisions and thus a large number of zero detecting circuits, and this has led to a disadvantage that the circuit construction thereof becomes complex.
The conventional device has also suffered from the disadvantage that the accuracy of division is poor due to the amplitude fluctuations or the like of the two sine signals.
A further disadvantage of the conventional device is that the accuracy of division is poor due to the so-called phase fluctuation of the two sine signals which is the deviation of the phase difference therebetween from 90.degree. resulting from temperature changes or the like.